Remote-control system



Feb i, 1949. I. F. CADMAN REMOTE CONTROL SYSTEM FiledFeb. 20, 1946 INVENTO 'IPaEUadmem Patented Feb. 1, 1949 n'so STATES e's'rs n'r' OFFICE REMOTE CONTROL SYSTEM Ira F. Cadman, Swissvale, Pa assignor to- The Union Switch & Signal Company, Swissvale, Pa, acorporati'on of-Pennsylvania Applicationl ebruary 20, 1946; Serial No.1 649,072

5 Claims.

My invention relates to remote-control systemsv and more particularlytorcentralizedtra-fficcontrolsystems. in whichlrtrafiic governingdevices located along, a trackwa-y are: governed from a control oliice and'the conditionsof the devices and associated. apparatusaare indicated at'such In systems of the type. described the-apparatua at thecontroloffice is linked with the traffic governing devices along-:the trackwaybymeans of a communication system whichmay be: either of :thedirect wire type;. or of thecodetype; one.

example ofv which is showniin'Letters.Patentzof the United StatesNos 2,229,249; granted to L..V. Leis on January 21, 1941. communication system provides. a number of.

control and communication channels, withthe indication: channels of: the code system comprising separate codestepsv each having. one dlstmce tive: character or another to indicaterdifierent conditions inthe, field. Twosuch channels are requiredto; indicate three difierent' conditions; of.

a movable device. is usually indicated overtwo channels arranged in such: manner that one channel indicateswhether or .not the switch is locked in its normal position; and-the other channel indicates whether. or not the switch'is locked in. its reverse position;

Thus when theswitch is locked in either :its normal or its, reverse.- position it provides-tone char? actor for the code step which indicates that. the switch ,isilocked in the-corresponding position, and providesaqdifierent character. for the. other code'step.

both have thediiierent character mentioned; to indicate the transit condition;

both have the one characterlreferred to,. but

the: switch obviouslyis-lnot adapted tO pIYOVid8I this character for both steps,- and tl'ieiull-ca pacit of the code is ordinarily not utilized.

One object of- .my inventioni is to provide means for utilizing the two indication channels'ofa a. centralized trafficcontrol. system which indicate three conditions ofa movable device,-to provide:

anv additional; indication of the: operation of-a two-position device whichotherwise: would: require the provision of- .an. additional JCOd step:

Another object of; my invention :is: to -p ovide meanslfor-"obtainingl; any additional. indication of" either=of two conditionsron two: indication steps-' of a code which ate normally:arranged.:toaproe In either case the For example; a. trackaswitch Whenthe switch: is unlocked by the switchmachine,v as Whenthe. switchpointsare in transit between extreme positions, the: ccde-intervals of the two switch indication .steps---.

The two. steps are capable of indicating a fourth-conditionif thenovel features thereof in. claims.

The accompanying, drawing is a diagrammatic view illustrating one-form of apparatus embodying my invention";

Referring tothedrawing, a centralizedv trafiic control systelnisi'epresented as comprising control-.andu-indication apparatus at'an ofiice and at alstation, anda communication system linking the oilice with thestationb Thewcommunication system, which may be of either thedirect wire or the code system, is con-- ventionally represented in the'drawing as being a; codesystem of the type illustrated in the previously mentioned Lewis patent. For the purposes ,of. explaining the present invention it is sufi'icientfitostate that the communication system provides a number of-control channels represented.inthe drawingtbylong-dash lines, and a number of indication channels-represented in the=;drawing; by,shor.t-dash lines,:with the wires of. each channel designated'byreference characters'which are thevsame as thoseused to designate corresponding wires in the patent. For example, the. control channel lei-6H and the indication channel" I Iii-33 represent individual code steps. of. ancontroloand indication code, respectively, and. thexsystem functions in the mannerexpl'ained-in the patent. so that'if one terminal B of alsuitablelocalsource of current at theofiice-isconnected tow-ire lBlwhen acontrol code is. transmitted, the code will include a step ot avparticular character corresponding to the energizationof channelliil-il, to cause terminal .B of: a source at the station to be applied to: terminal at: Similarly, if terminal 3 at the station isconnected to wire 93 when anindication .code is transmitted, the codeHwill include as step: corresponding to the. energization of. ll3-i-93ztoapplyj terminal: B at the:

channel oiiice to wire ll The apparatus at thel office, as indicated inthe 3 drawing, includes a starting key SK, effective when closed to connect terminal B to wire 97, to initiate the transmission of a control code to connect terminal B to wire 29 to complete a circuit through the Winding of the delivery relay D to the other terminal of that source.

The office apparatus also includes a switch lever WK for the remote control of a power operated track switch W, lever WK having two positions for applying energy to terminal iti or Hi3 respectively when starting key SK is pressed; a maintainers call key MCK by which the operator is enabled to light a lamp MCE to call the maintainer to the telephone provided in systems of this character, key MCK being effective when closed to apply energy to terminal an oifice delivery relay OD which is picked up at the office in response to energy applied to terminal H8 at the end of a complete indication code received from the station; and a normal indication relay NWK and a reverse indication relay RWK selectively picked up according as energy is applied to terminal l [3 or I H5 at the office when the ofiice delivery relay OD is picked up. After relay NWK or RWK is picked up, it is held energized over a stick circuit including its own front contact and a back contact of relay OD, when that relay releases at the end of the indication code. To visually indicate the position of the track switch W, a normal switch indication lamp NE and a reverse indication lamp RE are provided. Each of these lamps is arranged to be energized over a circuit including a front contact of the corresponding indication relay and a back contact of the other indication relay. An additional indication lamp POE is provided at the ofiice which is lighted to indicate the loss of the primary power supply at the station. Lamp POE is controlled over a circuit including in series front contacts and 5B of relays NWK and RWK; and a single stroke bell XB, controlled by a relay 1G,, is caused to sound when lamp POE becomes lighted. Relay XR is energized over a circuit including front contacts 57 and 58 of relays NWK and RWK, and has a continuity transfer or make-before-break type contact in which is effective momentarily when relay XR picks up to close a circuit for bell KB.

The apparatus at the station for governing the operation of track switch W includes a switch locking relay'LR, which is energized only when traific conditions adjacent the switch are safe to permit operation of the switch, like the relays LMR, RMR, TR, etc., which control relay WR of the Lewis patent. The switch is manually governed by a normal switch control relay NWS and a reverse switch control relay RWS. Relay NWS or RWS, respectively, is picked up according as energy is applied to terminal 3! Or 33 when delivery relay D and lock relay LR are picked up, and each switch control relay has a stick circuit including its own front contact and back contact of the other switch control relay and a back contact of delivery relay D, over which the operated switch control relay is held energized after relay D releases. The switch control relays NWS and RWS control a switch operating relay WR, which is supplied with energy of one polarity or the other according asrelay NWS or RWS is picked up, provided the lock relay LR also is picked up. Relay WR controls the supply of energy to a power operated switch operating mechanism SM provided for switch W.

The primary power supply from which energy for operating the station apparatus is derived is represented in the drawing by the reference characters ac connected to a primary winding ll of a transformer I2 having its secondary winding l3 connected to the input terminals of a rectifier R. The output terminals of rectifier R are connected across end terminals B and N of a battery i l, and normally supply rectified current to battery M to maintain it fully charged. A connection from terminal B to the contacts of relay WR, and a return connection to terminal N provide energy for operating relay WR and the motor of switch machine SM for switch W, and connections to terminals B and C of battery l4 provide energy for operating the apparatus at the switch location. The position of switch W is indicated by normal and reverse switch repeating relays NWP and RWP, which relays are selectively energized over a contact 15 operated by switch operating mechanism SM, provided switch W is locked in its normal or reverse position, respectively. The continuity of the primary power supply is indicated by a power-oil relay POR connected across primary winding H of transformer 52 and held energized as long as power is available from the alternating current source, When relay POR releases, a repeating relay PORA, of the slow-pick-up type, is energized over back contact [6 of relay POR. Relay PORA governs the transmission of an indication controlling the power-off lamp POE at the office.

The provision of this indication is of particular advantage in connection with a power operated track switch, because in the event of a power failure it enables the operator to call the maintainer promptly, to facilitate the correction of the fault and the restoration of the power supply before the switch battery M is fully discharged. The maintainers call is established by a relay MCR which isenergized by a control code transmitted from the onice when key MCK is closed, by energy applied to wire 36. When relay MGR picks up, it is held energized over a stick circuit including its contact It, usually until released by relay D, in response to a code transmitted when key MCK is open. The closing of contact 19 also completes a circuit for lamp MOE, which therefore is lighted as long as relay MCR is energized. Relay ST is the station starting relay of the code system, which when picked up initiates the transmission of an indication code by connecting terminal B to wire 38, which as indicated, applies energy to the office delivery relay OD to establish the indication channels 93-4 l3 and IS. A selector relay S is also operated by the code, which serves to release relay ST. Relays S and ST function like the similarly designated relays of the Lewis patent, and it is to be understood that the circuits for relay ST include additional branches, not shown herein, so that relay ST becomes energized in response to each change in the positions of relays NWP and RWP. Relay ST is also operated by relay D, to cause a return indication code to be transmitted following each control code.

The condition of the apparatus, as shown, is that obtaining when switch W has been operated to its normal position. At the ofiice, switch lever WK is in its normal position and normal indication relay NWK is energized over its stick circuit extending from terminal B at its front contact 20 over back contact 2| of relay OD and the winding of relay NWK to terminal C; and normal switch indication lamp NE is energized over a circuit includin back contact 22 of relay RWK and front contact 23 of relay NWK.

At the station, normal switch controlrelay NWS-is energized over a-circuitfrom terminal B at back contact 24" of relay D, over back con-' operator moves switch lever WK to its reverse position and presses starting key SK. Delivery relay D becomes energized and energy is applied through channel 193-33 to terminal 33 to pick up relay RWS; relay NWS being released when relay D picks up to open its back contact 24. The energization of relay RW'S and deenergization of relay NWS results in the energization of switch operating relay WR by current opposite in polarity to that supplied when relay NWS is picked up andrelay RWS is released, with the resultthat relay WR reverses its polar contacts, thereby causin the motor of switch machine SM to move switch W to itsreverse position.

The switch machine SM functions in theusual manner, and. its initial movement opens contact 55 as it unlocks the switch points to permit them to be moved to their reverse position, therebyreleasing relay NWP. Relay ST is picked up by relay D and initiates the transmission or" an indication code, and since this finds both relays NW? and RWP released, both channels 93-l'i3 and 95-4 are deenergized to indicate the unlocked or transit condition. Consequently when the ofilce delivery relay OD is operated, relay NWK releases and both indication lamps NE and RE become dark. When switch W reaches its reverse locked position, relay RWP is energized over contact l5, again energizing relay ST as explained in'the patent, to transmitan indicationcode to indicate that the switch is'locked reverse. In this instance channel 85-415 is supplied'with energy over front contact 42 of relay RWP so that when relay OD at the ofiice is oper ated, relay RWK is picked up to cause reverse switch indication lamp RE to become lighted. The operation of switch vW from its reverse to its normal position is carried out in a similarmanner, as will be readily understood.

Ittwill now be assumed that a failure ofthe A. C. power supply occurs, when the switch is locked normal or reverse as indicated by the lighting of lamp NE or RE- Due to the loss of the A; .0. power, POR releases to close its back contact Hi, and relay PORA becomes energized. During the slow pick-up period of relay PORA, a circuit is closed momentarily from terminal B at'back contact 5610f relayPOR over back con-- NWP is energized. at this time, terminal B at back contact 42of relay RWP is:connected to Wire 93 over front contact 4 3 of relay NWP; and" from wire 93 to wire 95'over contacts 52 and 53; while:-

ifrelay RWP is energized, terminal B is: connected over its front'contact iz 'to wire 95, and' 1 from wire 95 .to wire 93 over contacts 52 and531 It followsthat if the alternating current source of power should fail with theswitch lockedv in either its normal or reverse position, channels 93l l3 and 95-il5 are both energized so that F both relays NWK and RWKare picked up by the indication code, whereupon both switch indication lamps NE and RE become dark, and a circuit is closed including front contact 55 ofrelay and front contact 56 of relay RWK for indication lamp POE which thereupon becomes lighted to indicate a failure of power at the station.

Also, relay XR becomes energized over the circuit: including" front contact 51 of relay NWK and front contact 58 of relayRWK and during the audible indication of the power-=01? condition.

Both relays NWK and RWK will, of. course, be.

held energized by their respective stick circuits uponrelease'of relay OD at the ofiice, and the. power-01f indication will be displayed'by lamp In this case. the indication code initiated'tby the releaseof relay POR findsboth switch repeating relaysNWP and RWP released, consequently wires QSand'SS are deenergized and the code'repeats the transitindication, lamps POE, NE'andRll. remaining dark. In-this case, however, another indication code Will be initiated in response to the energization of relay NJVP or RWP as soon. as the switch completes itsmove ment and is locked by the switch machine, and

since relay PORA is energized, this code will" cause lamp; POE to be lighted in place of lamp".

NE or RE, as in the preceding example.

The operator may cancel the power-off indi cation displayed at the office, and restore the indications normally reflecting the position of the switch, by closing themaintainers call key MCK and momentarily pressing starting key SK. Thisresults in the energization of relay MGR, since:

wire 36 at the field station becomes energized and relay MGR. picks upover a circuit. from,

terminal B at wire 36 .over front contact iii of relay D, the winding of relay MGR, front con.-

tact H) of relay PORA and back contact 56 of relay POR. At this time front contact i9 ofrelay-MGR closes to prepare the stick' circuit for that relay and also to light the maintainers call lamp MGE. It willbe' noted that this code serves as an acknowledgment of the receiptof the power-01f indication by the operator, and

' also serves to call the maintainer to correct the fault; When relay MGR picks up, its front contact 53. opens the connection from wire 93. tov

95, and since relay ST has'been operated by relay D, an indication code will now be transmitted to the office reflecting receipt of the maintainers call control code at the station. In this code,

the switchindication steps will be controlled in.v the normal manner by switch repeating relays.

relays. NWK and RWK, and one or the other. of the latter relays will be held energizedpver a,

front contact of relay OD according as'terminal H3 or H5 at the office is energized over the indication channels provided by the communication system. The energized switch indication relay at the ofiice will, of course, light lamp NE or RE to provide the usual indication reflecting the position of the switch.

It will be seen that as long as relay POR remains released, the operator can select the poweroff indication or the switch indication at will, by transmitting control codes with key MCK open or closed, respectively, and he is thus able to ascertain whether or not the power supply has been restored.

It may happen that the power failure occurs after the operator has issued a call to the maintainer, and that back contact 53 of relay MCR. is open when relay POR releases. If the power should fail when relay MCR is energized, the stick circuit of relay MCR which includes back contact I8 of relay PORA is interrupted at front contact I6 of relay POR during the slow pickup period of relay PORA, so that relay MCR releases before front contact |8 of relay PORA closes to prepare the alternative stick circuit for relay MCR, which includes front contact E8 of relay PORA, and back contact iii of relay POR. It follows, therefore, that if relay MCR happens to be energized at the time that a power failure occurs it will be released automatically when relay POR drops, and back contact 53 of relay MCR will close and thereby enable front contact 52 of relay PORA to complete the circuit across wires 93 and 95 to indicate the power failure. This power-oif indication may be cancelled by again energizing relay MCR by actuation of key MCK, as hereinbefore explained.

The apparatus embodying my invention is therefore arranged to provide an additional indication which is of advantage in maintaining a power operated track switch, by making use of the two indication steps normall provided for indicating the condition of the switch, and provides a means whereby this additional indication may be cancelled at the will of the operator to restore the switch indications. Except when this additional indication has been acknowledged and cancelled, the lighting of a switch indication lamp not only indicates the position and locked condition of the track switch, but also indicates that power is available for a considerable number of operations of the track switch.

Although I have herein shown and described only one form of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In a remote control system, an ofiice and a station, a movable device at said station, a communication system linking said station with said ofilce and providing two indication channels over each of which code elements of one character or another may be transmitted, means for controlling said channels by said movable device so that the code element transmitted over one channel has one character or another depending upon whether or not said device is in a first position and that transmitted over the other channel has one character or another depending upon whether or not said device is in a second position, indication means at the oflice controlled in accordance with the characters of said two code elements to indicate when said device is in its first or second positions or in transit between said positions, a source of power at said field station, means for operating said movable device between its said first and second positions by power derived from said source, said operating means being manually controllable over said communication system from said oflice, a power-oi relay at said station connected with said source to reflect presence or absence of power, means controlled by said power-01f relay when reflecting absence of power for causing the code elements transmitted over said two indication channels to each have said one character, indication means at said oifice controlled in accordance with the character of said two elements to indicate the power-off condition, a stick relay at said station having a pick-up circuit manually controllable from said office and a stick circuit completed over either a front or a back contact of said power-off relay when said stick relay picks up, said stick circuit being interrupted momentarily to release said stick relay when said power-01f relay changes its condition to reflect a change in condition of said source, and means effective when said stick relay is picked up for rendering ineffective the control by said power-off relay over the characters of said two elements, whereby not more than one of said two elements is caused to have said one character depending upon the position of said device.

2. In a remote control system, an oflice and a station, a first movable device at said station, a. communication system linking said station with said office and providing two indication channels over which code elements of one character or another may be transmitted, means for controlling said channels by said first movable device so that the code element transmitted over one channel has one character or another depending upon whether or not said device is in a first position and that transmitted over the other channel has one character or another depending upon whether or not said device is in a second position, indication means at the office controlled in accordance with the characters of said two code elements to indicate when said device is in its first or second position or in transit between said positions, a second movable device at said station having a normal and an operated position, means controlled by said second movable device in its said operated position and effective when the code element transmitted over either of said two channels has said one character to cause the other to have said one character, indication means at said office distinctively indicating when the code elements transmitted over said two channels both have said one character, a stick relay at said station provided with a pick-up circuit manually controllable from said ofiice and a stick circuit including its own front contact and a contact closed by said second device in either the normal or operated position of said second device, said stick circuit becoming opened momentarily to release said stick relay, if energized, when said second device moves from its normal to its operated position, and means controlled by said stick relay when energized for preventing the control of said code elements by said second device in its said operated position.

3. In combination with a power operated railway track switch manually controllable from a control ofice, a normal and a reverse switch repeating relay controlled by said switch and arranged to be energized only when the switch is locked in a corresponding normal or reverse position, a normal and a reverse indication relay at said oliice, a communication system linking said switch repeating relays and said indication relays and providing two indication channels one for each indication relay for energizing such relay when energy is applied to the channel at said switch location, means controlled by each switch repeating relay when energized for applying energy to its channel to effect the energization of the indication relay controlled over such channel, a normal and a reverse switch indication lamp controlled by said indication relays for indicating the position of said switch, each having an energizing circuit including a front contact of the corresponding indication relay and a back contact of the other indication relay, a power-off relay at the switch location which is normally energized from t e primary source of power for said switch, means controlled by said power-off relay when released for establishing a connection between said two channels at the switch location to apply energy to both channels when either switch repeating relay is energized, a power-off indication lamp at the office having an energizing circuit including front contacts of both indication relays, and means manually controllable from said oflice for interrupting the connection between said channels established when said power-off relay is released.

4. In combination with a power operated railway track switch, a normal and a reverse indication relay at a control office, a communication system linking said switch location with said office and providing two indication channels, one for each position of said switch, means controlled by said switch for energizing the normal or reverse indication relay over its channel only when the track switch is locked in the corresponding normal or reverse position, a power-off relay deriving its energization from the primary source of power at the switch location, means controlled by said power-off relay when released for controlling said two indication channels to energize both of said indication relays, a stick relay manually controllable from said ofiice, means controlled by said stick relay effective if said relay is picked up after the power-off relay releases for discontinuing the control of said two indication channels by the power-off relay, means effective if the stick relay is picked up when the power-off relay is energized, for releasing the stick relay when the power-off relay releases, to render the power-off relay effective to control said two indication channels, and means at said office for visually indicating the condition of said indication relays.

5. In combination with a. power operated railway track switch, a normal and a reverse indication relay at a control office, a communication system linking said switch location with said office and providing two indication channels controlled by said switch, one for energizing said normal indication relay and the other for energizing said reverse indication relay, according to the position of the switch, a power-off relay normally energized from the primary source of power at the switch location, means controlled by said power-off relay when released for controlling said two indication channels to energize both of said indication relays, a relay at said switch location manually controllable from said office and having a circuit including either a, front or a back contact of said power-off relay which opens momentarily to release said manually controllable relay, if then energized in response to the release of said power-oil? relay, means controlled by said manually controllable relay when energized for preventing the control of said two indication channels by said power-ofi relay, a normal and a reverse indication lamp each having a circuit including a front contact of the corresponding indication relay and a back contact of the other indication relay, and a power-off indication lamp having a circuit including front contacts of both indication relays.

IRA F. CADMAN.

No references cited. 

